Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Stanford researchers study how gene level variations in blood affect immunity

13.02.2003


Differences in people seem to run in the blood, according to a recent study that examines which genes are active in blood cells. The work, published in this week’s online issue of the Proceedings of the National Academy of Sciences, found that the levels of several genes used by blood cells vary from person to person.



"Nobody had taken this broad a look at genetic variation in the blood of healthy people," said David Relman, MD, associate professor of medicine at Stanford and a co-author of the study.

People vary greatly in their reactions to bacteria and viruses; some individuals fall prey to every bug that comes along while others go through winter sniffle-free. Relman, along with Patrick Brown, PhD, professor of biochemistry, and research assistant Adeline Whitney thought these differences might show up when looking at which genes are active in circulating blood cells.


To find out the extent and nature of the differences in gene activity in people’s blood, Relman and his colleagues drew blood from 75 healthy people and extracted a molecule called RNA. RNA is produced by active genes and can be used to identify which genes are being expressed in a given sample. They then attached a fluorescent molecule to the RNA and applied the samples to a gene chip - a glass slide dotted with human genes. If a sample contained RNA corresponding to a gene on the chip, the fluorescently labeled RNA would bind to the spot and produce a visible signal. The bigger the signal, the more RNA was present, and therefore the greater the gene expression. Whitney then compared which spots varied in brightness among the samples.

The blood used in this analysis contained a variety of cells, including red blood cells that carry oxygen to the tissues and immune cells that fight disease. The red blood cells don’t contain nuclei and therefore don’t produce RNA. That leaves immune cells as the only cells making RNA in the blood sample. Any differences found in the pattern of active genes resulted from these disease-fighting cells.

A few genes stood out as being used at varying levels in different people. Some of these could be used to distinguish between men and women. For example, women use different levels of genes whose proteins respond to an immune protein called interferon. Researchers had suspected that genes in the interferon pathway might have a role in the higher risk of autoimmune diseases among women.

The researchers also found variations in two genes that weren’t previously documented as being active in blood cells. One is a gene that makes the prion protein - the protein altered in people who have Creutzfeldt-Jakob disease. Another surprisingly variable gene was BRCA1, which is mutated in an inherited form of breast cancer. It could turn out that levels of the prion protein or BRCA1 in the blood play some role in determining the risk for prion-related diseases or cancer.

In addition to the variation of gene expression among different people, the researchers found genes that varied according to the time of day that blood was drawn. Other genes were used at higher or lower levels depending upon the age of the blood donor - a finding that could eventually help doctors understand why older people are more prone to some illnesses.

Relman pointed out that it’s too early to know why people use genes at higher or lower levels in blood cells, and the consequences of this variability. "It may be that some people confronted a virus or had a cold the week before, or had different environmental experiences," he said.

He added that despite the differences, there was remarkable similarity in the genes used in the blood cells among the study subjects. "It was surprising that the degree of variability was as small as it turns out to be," he said. This finding bodes well for using gene expression in blood to distinguish between healthy people and those with an infectious disease. Because people are usually quite similar, any disease-related variation should stand out.


Other Stanford researchers who contributed to the paper include MD/PhD students Maximillian Diehn, PhD, and Ash Alizadeh, PhD; postdoctoral fellow Stephen Popper, DSc; and medical student Jennifer Boldrick.

Stanford University Medical Center integrates research, medical education and patient care at its three institutions - Stanford University School of Medicine, Stanford Hospital & Clinics and Lucile Packard Children’s Hospital at Stanford. For more information, please visit the Web site of the medical center’s Office of Communication & Public Affairs at http://mednews.stanford.edu.

PRINT MEDIA CONTACTS: Amy Adams at (650) 723-3900 (amyadams@stanford.edu)
BROADCAST MEDIA CONTACT: Neale Mulligan at (650) 724-2454 (nealem@stanford.edu)

Neale Mulligan | EurekAlert!
Further information:
http://med-www.stanford.edu/MedCenter/MedSchool/

More articles from Health and Medicine:

nachricht Malaria Already Endemic in the Mediterranean by the Roman Period
27.07.2017 | Universität Zürich

nachricht Serious children’s infections also spreading in Switzerland
26.07.2017 | Universitätsspital Bern

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Physicists Design Ultrafocused Pulses

Physicists working with researcher Oriol Romero-Isart devised a new simple scheme to theoretically generate arbitrarily short and focused electromagnetic fields. This new tool could be used for precise sensing and in microscopy.

Microwaves, heat radiation, light and X-radiation are examples for electromagnetic waves. Many applications require to focus the electromagnetic fields to...

Im Focus: Carbon Nanotubes Turn Electrical Current into Light-emitting Quasi-particles

Strong light-matter coupling in these semiconducting tubes may hold the key to electrically pumped lasers

Light-matter quasi-particles can be generated electrically in semiconducting carbon nanotubes. Material scientists and physicists from Heidelberg University...

Im Focus: Flexible proximity sensor creates smart surfaces

Fraunhofer IPA has developed a proximity sensor made from silicone and carbon nanotubes (CNT) which detects objects and determines their position. The materials and printing process used mean that the sensor is extremely flexible, economical and can be used for large surfaces. Industry and research partners can use and further develop this innovation straight away.

At first glance, the proximity sensor appears to be nothing special: a thin, elastic layer of silicone onto which black square surfaces are printed, but these...

Im Focus: 3-D scanning with water

3-D shape acquisition using water displacement as the shape sensor for the reconstruction of complex objects

A global team of computer scientists and engineers have developed an innovative technique that more completely reconstructs challenging 3D objects. An ancient...

Im Focus: Manipulating Electron Spins Without Loss of Information

Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.

For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

Closing the Sustainability Circle: Protection of Food with Biobased Materials

21.07.2017 | Event News

»We are bringing Additive Manufacturing to SMEs«

19.07.2017 | Event News

 
Latest News

Programming cells with computer-like logic

27.07.2017 | Life Sciences

Identified the component that allows a lethal bacteria to spread resistance to antibiotics

27.07.2017 | Life Sciences

Malaria Already Endemic in the Mediterranean by the Roman Period

27.07.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>